Distillate fuel oil compositions



United States Patent 3,014,793 DISTILLATE FUEL OIL COMPOSITIONS George A. Weisgerber, Iselin, and Gordon W. Duncan,

Westfield, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Filed Feb. 28, 1956, Ser. No. 568,151 8 Claims. (Cl. 44-66) This invention pertains to the stabilizing of petroleum oils against the formation and precipitation of sediment in storage. The invention relates to petroleum fuel oils and particularly to fuel oils known in the petroleum industry as gas oils, which are petroleum distillates intermediate in volatility between kerosene and lubricating oil and which are used as fuel in domestic heating furnaces and in diesel engines. These fuel oils are apt to form sediment in storage when they contain gas oils produced by cracking petroleum and particularly when they contain at least ten percent by volume of such gas oils of cracking origin. In accordance with the present invention the tendency for these fuel oils to form sediment is inhibited by incorporating in them small amounts of a tertiary alkyl primary amine wherein the alkyl radical is a hydrocarbon group containing at most 30 carbon atoms, at least eight carbon atoms and preferably 12 to 16 carbon atoms, of which at least one is tertiary and wherein the primary amino radical is attached to a tertiary carbon atom of said alkyl radical, a tertiary carbon atom being one that has three of its four valences fulfilled by chemical bonds with three other carbon atoms. The present invention is further concerned with fuel oil compositions containing said primary amines and also small amounts of surface-active compounds such as oil-soluble phosphates, alkyl phenol sulfides, sulfonates, naphthenates, amino-phosphatides, and phospho-sulfurized petroleum hydrocarbons. It relates to fuel oil compositions (1) that are stabilized against sediment formation, (2) that are stabilized against color degradation, and (3) that inhibit the corrosion of ferrous metals. Many of these fuel oil compositions are also characterized by the fact that they form little or no ash upon combustion.

Petroleum distillate fractions of the class of gas oil find wide use as fuel oils in the burner systems employed in domestic and industrial heating systems and as diesel fuels. It is common practice to incorporate cracked bydrocarbon stocks in these fuels, a fact which has given rise to a sediment formation problem. It has been found that the use of by volume or more of cracked stocks in these hydrocarbon fuels causes the formation of sludge or sediment during the time the fuel is in storage, and this sediment then later causes plugging or fouling of the filters, lines and nozzles in the burner systems in which they are employed. It has further been found that the formation of sediment is often accelerated by the presence of copper, a metal that is used extensively in many fuel oil systems.

Several other problems have also been encountered with distillate fuels. These problems include the corrosion of ferrous metals such as carbon steel, cast iron, etc., with which the fuels come in contact. The degree of corrosion is particularly noticeable when the metals are contacted by the fuels in the presence of water or an atmosphere containing water vapor. Further, some materials that have been added to these fuels to stabilize them against sediment formation have given rise to emulsion problems, occasioned when fuels containing these additives are contacted and agitated with water. It has been found that certain additives under these conditions cause the water and oil to form emulsions that are extremely stable and difficult to resolve. Finally, it is desirable to have these fuel oils be stable against any color degradation.

Accordingly, it is a primary object of the present invention to improve the stability of petroleum fuel oils against the formation of sediment, when these fuels contain 10% "ice or more by volume of cracked stocks. The particular oils embraced by the present invention include the fuel oils falling within A.S.T.M. specification, D39648T, for fuel oils (grades 1 and 2). Also useful in accordance with the present invention are diesel fuel oils No. l-D, No. 2D, and No. 4D of A.S.T.M. specification D-975-51T.

Additional objects of the present invention include improving the color stability and the anti-corrosion characteristics of these oils, and also minimizing or completely eliminating the formation of ash from the improving additives when the improved fuels are burned.

In accordance with the present invention, fuel oils are stabilized against sediment formation by the addition of from about 0.001 to 1.0 wt. percent of a primary amine in which the carbon atom attached to the amino group is a tertiary carbon atom.

Tertiary alkyl primary amines suitable for use in ac cordance with the present invention can be prepared from tertiary olefins, for example polymers of propylene or isobufene and from copolymers of propylene and isobutene, as well as from copolymers of isobutene and butenes or pentenes.

Such polymers and copolymers are well known synthetic olefins in the petroleum industry. For instance, propylene polymers ranging in molecular size from the dimer of six carbon atoms to the tetramer of twelve carbon atoms are made, in mixtures of suitable volatility for use in motor gasoline, by polymerizing propylene in the presence of catalysts which are made by impregnating silica gel suitably with phosphoric acid. Also, in the manufacture of iso-octane for use in aviation gasoline, isobutene has been converted to diisobutene by polymerization with sulfuric acid as catalyst and then to iso-octane by hydrogenation. Of course, the manner of preparation of the polymers or olefins is not at the point of novelty of the present invention, nor is the manner of preparation of primary amines from olefins, which as is Well known, can be aminated with ammonia. Suffice it to say that an olefin like the dimer of isobutene can be converted, for example, to 2- amino-Z,4,4-trimethyl-pentane and 2 amino 2,3,4 trimethyl-pentane, each of which is a primary amine having an amino radical attached to a tertiary carbon atom in an alkyl group of eight carbon atoms arranged in a branched chain.

In both of the examples above, the amino radical is attached to a tertiary carbon atom which is actually the second carbon atom in the longest chain of the alkyl group. That is a normal attachment when the alkyl group is derived from a polymeric olefin which naturally tends to end with a double bond; but even though that structure naturally predominates there occur various isomerizations and migrations through which other structures result and produce double bonds elsewhere than at the end of the longest chain. In a polymerization not only structural variations but also irregularities of molecular weights oc our; and at any given set of conditions of reaction the final equilibrium produces a mixture of olefins.

Consequently, the tertiary alkyl primary amines, suitable for use in accordance with the present invention, when they are made from tri-isobutene, which is a polymer of isobutene having tertiary carbon atoms in a molecule containing 12 carbon atoms, may contain some tertiary alkyl amines of l3, 14 and/or 15 carbon atoms as well as the predominant one of 12 carbon atoms. Such a mixture is conveniently designated as a tertiary alkyl primary amine having predominantly 12 carbon atoms per molecule and having minor proportions of homologous molecules with l3, 14 and/or 15 carbon atoms. Similarly, when making a suitable tertiary alkyl primary amine of 18 carbon atoms from hexa-propylene,

a polymer of propylene, one obtains a mixture conveniently designated as t-C H NH which in context is understood to be a tertiary alkyl primary amine having predominantly 18 carbon atoms per molecule and having minor proportions of homologous molecules with 19, 20, 21, 22, 23 and/or 24 carbon atoms.

Specific examples of tertiary alkyl primary amines suitable for use in accordance with the present invention are the following:

6-amino-2.2,4,4.6,8,S-heptamethyl-nonane 2-amino-2.3,4,6,6,8,8-heptamethyl-nonane 4-amino-2.3,4,6.6.8,8-heptamethyl-nonane 4-amino-2,4,6-trimethyl-nonane 3-amino-3,5.8-trimethyl-nonane 3-amino-3,4,6-trimethyl-nonane 3-amino-3,6-dimethyl-decane 3-amino-3,S-dimethyl-decane 4-amino-4-methyl-undecane 4-amino-2,4,6,8, 10-pentamethyl-tridecane 3-amino-3,5,7,9,l2-pentamethyl-tridecane S-amino-S,13-dimethyl-hexadecane Specially preferred for use in accordance with the present invention is the material designated as which was made from tetrapropylene and which by actual analysis upon degradation to its constituent olefin by reaction with nitrous acid was shown to consist essentially of tertiary dodecyl primary amine. Particularly preferred concentrations of amines in a fuel are from 0.005 to 0.2 wt. percent and especially 0.005 to 0.02 wt. percent.

While the fuel oil compositions described above are particularly stabilized against sediment formation, the quality of the compositions can be further improved by the addition of certain surface-active compounds, particularly the oil-soluble phosphates, amino-phosphatides, and phospho-sulfurized petroleum hydrocarbons. All of these compounds have detergent properties, and some of them are also rust preventives.

Oil-soluble phosphates suitable for the purposes of the present invention include phosphoric acid esters of aliphatic alcohols having from 6 to 20 carbon atoms. Any such ester may be a single species or a mixture of monoor di-esters of primary and secondary alcohols with various phosphoric acids. Especially attractive alcohols for preparing the phosphoric acid esters are the C C Oxo-alcohols, which are conventionally prepared from C to C olefins by the well known Oxo process. In accordance with the 0x0 process an olefin is reacted with carbon monoxide and hydrogen at 2000- 4000 p.s.i.g., and 225-400 F., in the presence of a cobalt-type catalyst to form an aldehyde with one or more carbon atom than is possessed by the initial olefin. The aldehyde is then hydrogenated to the corresponding aliphatic alcohol. It will be noted that the alcohols produced by this process are primary alcohols with relatively large proportions of branched chains.

In petroleum refineries the olefins employed in the 0x0 process are conventionally formed by polymerizing and copolymerizing olefins such as ethylene, propylene and the various butylenes. A typical plant stream, for example, may contain 15-60 mol percent of propylene, 0.5- 50 mol percent of n-butenes, 0.1- mol percent of i-butylene and trace amounts of other hydrocarbons. It will be appreciated that the product formed by polymerizing such a stream will consist of a large number of olefins having various molecular weights and structural configurations. The polymerization may be carried out at 300-500 F., and 250-5000 p.s.i.g. in the presence of a phosphoric acid catalyst. Illustrative of the type of alcohols obtained by the oxonation of C olefins (in turn obtained by the polymerization of a mixture of C and C olefins) is the following analysis of a C Oxo alcohol.

The C -C aliphatic alcohols may be esterified with phosphoric acid in any conventional manner. The Oxo alcohol-phosphoric acid esters are preferred and especially the C Oxo phosphoric acid esters. A particularly attractive alkyl phosphate is the di-alkyl C Oxo ester of phosphoric acid hereinafter designated as Additive LR.

Especially effective sulfonates are the oil-soluble ammonium petroleum sulfonates and the oil-soluble alkyl benzene sulfonates with which the preferred amines can act synergistically for stabilizing the oils against sediment formation in the presence of metals. Preferred sulfonates are those derived from petroleum sulfonic acids having molecular weights of about 380 to 550.

Preferred surface-active agents for use with the primary amines described earlier are the oil-soluble phosphatides including the various lecithins which are the choline-phosphoric-acid mono-esters of the diglycerides of oleic, stearic or palmitic acid and which have the general structural formula:

in which the RC0 groups are oleoyl, searoyl, palmitoyl, or other acyl radicals of fatty acids. Lecithin is readily available as such in a commercial grade that contains amounts of other phosphatides such as cephalin and lipositol. This commercial grade is very effective in the compositions of the present invention.

Phospho-sulfurized hydrocarbons that are employed in conjunction with the amines of the present invention may be prepared by treating hydrocarbons having a viscosity above about 50 S.S.U. 210 F. with from 5 to 25 wt. percent of a phosphorus sulfide at a temperature of 375 to 475 F. and preferably 400 to 430 F. It is preferred that from 10 to 20 wt. percent of the phosphorus sulfide be employed and that the time of treatment be from 1 to 20 hours. The reaction is preferably continued for several hours, for example, 10 hours or so, and until the hydrocarbon product has a phosphorus content of about 2% to 6% by weight and a sulfur content of about 5% to 12% by weight. The treatment should not be extended to the point where the product becomes insoluble in the fuel oil in which it is to be used.

Preferred hydrocarbons for phospho-sulfurization are lube oil base stocks and especially bright stocks having for example an S.S.U. viscosity at 210 F. in the range from about to 250 seconds. They may be obtained, for example, by deasphalting, dewaxing, acid-treating, clay-treating, etc. of various petroleum residua. The higher molecular weight parafiins, aromatics, cyclic aliphatics, alkaryl compounds and the like may be used. Petrolatums, waxes, solvent extracts of petroleum fractions, etc. are also suitable.

The phospho-sulfurized hydrocarbons are preferably neutralized to reduce their titratable acidity and thereby increase their stability. Their instability is evidenced by a high degree of corrosiveness toward copper and also by an objectionable odor.

The titratable acidity of the phospho-sulfurized hydrocarbons may be reduced by treatment with suitable basic reacting compounds such as the hydroxides, carbonates or oxides of alkali or alkaline earth metals, ammonia, alkyl or aryl substituted ammonia compounds such as amines or guanidine and derivatives thereof. Stability may also be improved by treatment with about 2 to 50 weight percent based on the total material of a suitably active olefinic hydrocarbon. By suitably active is meant that the olefinic material has the prop erty of reacting with loosely bound sulfur in the phosphsulfurized oil. Preferred olefins include the terpenes, terpineol, and the like and olefinic hydrocarbons such as isobutylene, diisobutylene, and the more reactive of the analogous aliphatic and cycloaliphatic materials. Such a process is described in U.S. Patent 2,640,053.

These ingredients may be mixed together at temperatures of 60 to 400 F. and from about 1 to hours until the desired degree of stability is attained. The reaction time may be as much as hours.

Again, the stability may be improved by treatment with about 0.1 to 5.0% and preferably 0.5 to 2.0 wt. percent of an unsaturated ester based on the phosphosulfurized hydrocarbon. Preferred unsaturated esters are unsaturated alcohol esters of monocarboxylic acids, which may be prepared by conventional esterifying means. This is described in U.S. Patent 2,694,044.

Concentrations of 0.001 to 0.5 wt. percent of the various types of surface-active agents described above are suitable for use in conjunction with primary amines of the type defined by the present invention. Particularly preferred concentrations of such surface-active agents are from 0.001 to 0.05 wt. percent of a heating oil and especially 0.002 to 0.010 wt. percent.

The various additives mentioned above, both of the amine and surface-active types, may be added directly to a fuel oil as such or in the form of an oil-soluble concentrate. A suitable oil solvent for the preparation of a concentrate is preferably an oil of good quality, for example, a solvent-extracted parafiinic or Mid-Continent neutral oil falling within a viscosity range at 210 F. of 30 to 120 S.U.S. or a stable fuel oil of any of the grades hereinbefore designated.

0f the various amine additives described herein, the tC H NH additive is especially preferred. Of the various surface-active additives to be used in combination with the amine additives and especially the amine additive just named, the lecithin additive is particularly preferred.

The nature of this invention will be more fully understood from the following examples:

EXAMPLE I A conventional heating oil was tested for stability against sediment formation as the oil was received and again after addition of various types of additives to the oil. The oil in this example and in all of the following examples was a blend consisting of about by volume of catalytically cracked stock, about 50% by volume thermally cracked stock, and about 20% by volume of virgin stock. Typical inspections of this type of oil, for which the respective components may be varied from 10 to 50%, 10 to 50% and 5 to 80% in the order named above, are as follows:

6 A.S.T.M. distillation range:

I.B.P., F. 330 10% 420 50% 500 585 Final boiling point, F. 645 Conradson carbon residue Trace Typically, these fuel oils boil between the limits of 300 F. and 700 F.

The stability characteristics of this heating oil by itself, and in combination with various amine additives, are indicated in the following table. In each instance the oil sample or blend was heated for a period of either 16 hours at 210 F. or for 14 days at F., and the amounts of sediment formed during these heating periods were then isolated and measured.

Table I HEATING OIL STABILITY TESTS+(SEDIMENT FORMA- TION)EVALUATION OF INHIBITORS Mg. sediment/600 g. 011

Blend Tested 16 hrs. at 14 days at 0 F.

Heating oil, uninhibited +0.50% straight-chain aliphatic primary amine.

+01% straight-chain aliphatic primary amine.

+05% straight-chain aliphatic primary amine.-

+01% straight-chain aliphatic primary amine.

1 li-Clt-isHta-ZINH: hereinafter identified as Additive P. 2 A mixture of straight chain primary amines having the following approximate composition:

C isHzsN Percent 90 CrsHzeNHz Percent 90 CwHaaNHz C1x a1NHz oisHsaNHz 4 Referring to the above table, it will be noted that the addition of small amounts of a primary amine containing a tertiary carbon atom immediately adjacent the amino group to a heating oil markedly reduces the sediment forming tendencies of the heating oil. It will also be noted that the addition of straight-chain alkyl primary amines containing no such tertiary carbon atom to a heating oil does not improve the stability of the oil, but instead, actually renders it less stable. The latter type of amines have found wide application as Wetting agents, rust preventives, and demulsifiers in various oil fractions; but it is apparent from Table I above, that these amines are far inferior to the amines disclosed in the present invention for stabilizing heating oils against sediment formation. It will also be noted that concentrations of the amines of the present invention in excess of 0.005 wt. percent are very effective in reducing the amount of sediment formed by a heating oil containing cracked stocks. When a concentration of the amine is at least 0.01%, the stabilizing influence is especially pronounced.

EXAMPLE II A heating oil of the same type and source as that employed in Example I was blended with an amine of the type defined in the present invention along with small amounts of oil-soluble surface-active agents. The various blends were then subjected to a number of diiferent tests to determine their color stability, sludging tendency, emulsion stability, and rust-preventive ability.

The color stability of the oil and of the various oilinhibitor blends was determined by heating an appropriate sample for a period of 16 hrs. at 210 F., in one test procedure, and for 14 days at 150 F. in a second test 8 i It will be noted that Additive P, which is in reality t-C H NH is a particularly attractive amine to use as a fuel oil additive. It greatly reduces sediment procedure. Following the heating period, each sample formation in the absence of copper. It also markedly was filtered and the percentage of white light transmitted 5 increases the color stability of fuel oil and decreases the through the filtered oil was determined and compared stability of the emulsions that a fuel oil forms with water. with the amount of white light transmitted through the It will also be noted that small amounts of a tertiary sample before heating. alkyl primary amine in combination with a surface-active The sediment forming tendencies of the samples were agent of the types described earlier herein greatly enhance also ascertained by two procedures. A first procedure the quality of a fuel oil. Not only is the sediment-formconsisted of heating a sample for a period of 16 hrs. at ing tendency of the fuel oil reduced, but other properties 210 F., and then determining the weight of sediment of the oil are also improved. For example, formed during this period. According to a second test procedure a sample was heated for. 14 days at 150 F. 25 the i slldge tlccgmulatmg during this penod 15 and lecithin, when jointly added to a fuel oil, decrease t i i i y g f' 1 d t the fuel oils sedimentand color-forming tendencies and g g i i Sta fi O 9 a 6 also greatly improve its resistance toward rust and emulmmg f y 3 mg ig e.wlt 0 y 2' mm sion formation. In addition, this particular additive water I g g? z i ortan o1 composition has a synergistic effect in reducing the sedito g C $19 i 18 s 1 5 .i 20 ment-forming tendency of a fuel in the presence of cope e i Blond m W1 per. It is also characterized by the fact that it is sub- Wlt water.m actua procesimg an an mg opeiatlons' stantially non-ash-forming since it does not contain any The rusting tendency of 011 samples was determined by metal constituents mlxlpg each Sample by Volume of water; then It is apparent from Table II that other tertiary alkyl shaking for 30 seconds, adding a polished mild steel (SAE #1020) test anel and shakin a aim for 30 secpnmary ammes such as t'C1844H3L49NH2 are effecnve p g g in increasing the stability of petroleum fuel oils. It is onds. The extent of rusting in both the water layer and also apparent that the elfectiveness of these amines is inthe water-saturated oil layer was observed after room creased by small amounts of surface-active agents such as temperature aging of approximately one month. 7 the 81k 1 esters of hos horic acid The sediment and color stability tests were run both y p P in the presence and absence of copper. EXAMPLE III The effectiveness of the amines alone and in combination with oil-soluble surface-active agents is clearly Samples of a h g 011 of the 581116 ype as that emindicated in the following table, where the results of ployed 1n Examples and II, b t aving slightly different th arious tests described abov re listed. stability characteristics were blended with an amine of Table 11 Mg. insoluble sediment/ g. 011 Color Stability Rusting Tendency Cone. of Additive in Heating Oil, Wt. 16 hrs. at 210 14 days at 150 16 hrs. at 210 14 days at 150 Emulsion percent F. F. F. 1*. Stability Water Phase 011 Phase No Cu With No On With No Cu With No 011 With Cu C11 C11 Cu 32.8 82.7 20 79 45 71 1 day. 2. 4 2. 4 86 ea. 3 hrs. 0.01 Additive P .3 70.2 g 3' 1 33 32 Do.

0.02AdditiveP 54.4 as 79 0.04 Additive P 1.1 1.6 91 2 days. 0.10 Additive P-. 1.2 1.5 87 a0 lday.

0.005 Additive. 3.1 05.0 3.8 72 23 73 0.01 Additive J. 1.5 01.0 1.0 81 20 77 32.2 55.3 22.4 78 57 08 20.1 40.2 10.4 74 01 02 2.2 4.8 5.0 49 34 58 1.0 2.0 02 30 48.6 50.7 01 52 1 day. 2.1 44.2 2.7 15.0 80 47 83 ca. 3hrs. 0.7 14.8 0.0 2.2 85 38 80 D0. 10 {ggfgggggg 0.0 1.0 s0 s4 ..do....... Do.

' 0.9 1.0 02 s5 do 18 --{8I8E A SAEE$ I} 1.3 1.6 9 4 "N do Do.

10 {ggmggggg E 1.0 1.4 as s1 do (in Do.

20 3.1 3.0 71 s2 d0 -.d0 Do. 21 Lecithm 0.0 0.3 0.0 1.5 so 20 70 02 heavy medium...

1 11 6" copper sheet immersed in oil during heating.

Additive J: t-Ciru Harte N Hi.

As may be seen in Table II, small concentrations of a the type defined in the present invention. Samples were tertiary alkyl primary amine are very effective in reducing 70 also blended with small amounts of phospho-sulfurized the sediment forming tendency and increasing the color hydrocarbons and with ammonium sulfonate in the presstability of a petroleum distillate fuel oil. Where the ence and absence of the amine. The resulting blends concentration of such an amine is about 0.1%, based on and samples were then evaluated for their colorand the fuel oil, this additive imparts some rust preventive sediment-forming tendencies. The results of the necesproperties to the oil. 75 sary tests are shown in Table HI.

Blend, Wt. Percent Additive N With N 0 With Cu Cu 3 011 Cu 1.--. 100% Heating Oil 35. 2 65. 3 81 48 2 0.02% Additive P--." 1. 4 54. 4 85 33 3 0 02% Additive LB 4 27. 8 69. 6 35 43 4-- 0 05% gditive LB 20. 48.1 13 25 5---- igg- -g- 1. 4 1o. 2 s3 37 1 live 6-.--

igi g g Smmnate a 9 22.1 87 41 inve {0.0173 Ammonium Sulfonate L 6 84 57 8---. 0.02% Ammonium Sultanate L 51. 6 129.0 45 25 9.--- 0.02% Ammonium Sulfonate L 73.1 74.0 37 37 1 Mg. sediment per 600 g. oil after heating 16 hrs. at 210 F. 2 Percent transmission of white light through filtrate after heating 16 hrs. at 210 F. relative to unheated oil as 100%.

3 X 6" copper sheet immersed in 011 during heating. 2o

4 (170 SSU vise. at 210 F. bright stock+10% P S )+4% vinyl acetate.

5 Oil solution containing 33%,% ammonium petroleum sulfonate.

6 Oil solution containing 50% ammonium petroleum sulionate.

The data in Table III again clearly indicate that an amine of the type defined in the present invention is very effective in stabilizing a fuel oil. that a fuel oil is stabilized even more effectively by the addition of small amounts of a phospho-sulfurized hydrocarbon or of ammonium sulfonate along with the amine. In fact, the amine co-acts synergistically with either of these two surface-active agents in stabilizing a fuel oil in 30 the presence of copper.

EXAMPLE IV A number of diesel fuel oils and a heavy catalytic rust tests as were employed in Examples I, II and III. Each oil was also blended with 0.014 wt. percent of an additive comprised of one part of t-C H NH and one part of commercial lecithin by weight and again subjected to the same test procedures. tests are given in Table IV below. It will be noted that each of the diesel fuel oils contained cracked stocks and met with various accepted specifications for such fuels. In the table, each of the diesel fuels is identified by the The data also indicate 25 The results of these distillate hydrocarbon fractions, it also has application to fuel oils that contain small amounts of residual hydrocarbons. It is contemplated that the present invention would be effective in fuel oils containing up to 10% or more of residual hydrocarbons.

This application is a continuation-in-part of Serial No. 318,320, filed November 1, 1952, now abandoned.

What is claimed is:

1. A petroleum fuel oil composition of improved stability having a boiling point range between 300 and 700 F. and containing at least 10 volume percent of petroleum hydrocarbons derived from cracking operations and to which has been added from 0.001 to 1.0 weight percent of a tertiary alkyl primary amine having 8 to 30 carbon atoms with a tertiary carbon atom attached directly to the amine group and from 0.001 to 0.5 weight percent of an oil soluble additive compound selected from the group consisting of:

(a) a phosphosulfurized hydrocarbon obtained by treating substantially olefin free lubricating oil bright stock having a viscosity of between 150 and 250 SSU at 210 F. with from 5 to 25 weight percent of a phosphorus sulfide at a temperature of from 375 to 475 F. to yield a phosphosulfurized hydrocarbon having a phosphorus content of from 2 to 6 weight percent, and

(b) lecithin,

said fuel oil composition having improved storage stability characteristics when in contact with deleterious metals that induce instability by the formation of sediment.

2. A fuel oil composition as defined in claim 1 wherein said olefin free hydrocarbon is treated with from 10 to 20 weight percent of phosphorus sulfide at a temperature of from 400 to 430 F. for l to 20 hours.

3. A fuel oil composition as defined in claim 1 wherein said phosphosulfurized hydrocarbon is stabilized by the treatment of said phosphosulfurized hydrocarbon with from 0.1 to 5.0 weight percent of vinyl acetate at a temperature of from to 400 F.

4. A fuel oil composition as defined by claim 1 wherein said tertiary alkyl primary amine contains from 12 to 15 carbon atoms and is employed at a concentration of particular set of specifications that it meets. 45 from 0.005 to 0.2 weight percent.

Table IV DIESEL FUEL STABILIZATION Insoluble Sediment, Color Stability Rust Test mg./600 cc. Fuel Sample Fuel Type No With N 0 On With Water Oil Phase Copper Copper Cu Phase A ASTM 975-511 (2-D) 17.7 44.6 97 Heavy-.. Medium. A+Additive do 1.6 14.0 100+ 86 None None. B 9.9 8.3 84 73 Trace... Do. 0.9 1.3 48 D0. 10. 4 32. 0 67 Light. 1.0 0.9 None. 9. 2 42. 9 Medium. 1.6 9.4 None. E 3 16.3 18. 4 v. Heavy. E-l-Additive 1.3 10.9 None.

1 Additive in all cases is 1:1 tlZ-ISHZS-HINH2 and lecithin (commercial grade). Fuel D corresponds to MIL-F-896 (Class 1) except that it contains 30% of thermally cracked stock.

8 A 100% cracked stock possessing the following inspections: Gravity. API 26 Distillation: Aniline Point, F 20% at 620 F. Wt. percent Sulfur" 1 80% at 720 F. Specific Dispersion 180 Percent off at 430 F.

It is apparent from Table IV that diesel fuel oils can be effectively stabilized by the addition of an additive of the type described in the present invention. In general, the particular additive evaluated in Table IV is markedly successful in reducing the sediment-forming, colordegradation, and rusting tendencies of diesel fuels.

It will be noted that while the present invention is di- 5. A fuel oil composition as defined in claim 1 wherein said composition has improved stability in contact with 70 copper.

6. A petroleum fuel oil composition of improved stability having a boiling point range between 300 and 700 F. and containing at least 10 volume percent of petroleum hydrocarbons derived from cracking operations rected primarily toward fuel oils composed entirely of 75 and to which has been added from 0.005 to 0.2 weight percent of a tertiary alkyl primary amine having 8 to 30 carbon atoms with a tertiary carbon atom attached directly to the amine group and from 0.001 to 0.05 weight percent of lecithin, whereby said fuel composition has improved storage stability characteristics when in contact with copper metals that induce instability by the formation of sediment.

7. A fuel oil composition as defined by claim 6 wherein said tertiary alkyl primary amine contains from 12 to 15 carbon atoms and is employed at a concentration of from 0.005 to 0.02 weight percent.

8. A petroleum fuel oil composition of improved stability having a boiling point range between 300 and 700 F. and containing at least 10 volume percent of petroleum hydrocarbons derived from cracking operations and to which has been added from 0.005 to 0.2 weight percent of a tertiary alkyl primary amine having 12 to 15 carbon atoms with a tertiary carbon atom attached directly to the amine group and from 0.001 to 0.05 weight percent of an oil soluble phosphosulfurized hydrocarbon obtained by treating substantially olefin free lubricating oil bright stock having a viscosity of between 150 and 250 SSU at 210 F. with from 10 to 20 Weight percent of a phosphorus sulfide at a temperature of from 400 to 430 F. for l to 20 hours to yield a phosphosulfurized hydrocarbon having a phosphorus content of from 2 to 6 weight percent and stabilizing said phosphosulfurized hydrocarbon with from 0.1 to 5.0 weight percent of vinyl acetate at a temperature of from 60 to 400 B, said fuel oil composition having improved storage stability characteristics when in contact with copper metals that induce instability by the formation of sediment.

References Cited in the file of this patent UNITED STATES PATENTS 2,005,619 Graves June 18, 1935 2,437,041 Proell Mar. 2, 1948 2,582,733 Zimmer et al Jan. 15, 1952 2,636,858 Jones et al. Apr. 28, 1953 2,672,408 Bonner Mar. 16, 1954 2,684,292 Caron et a1. July 20, 1954 

1. A PETROLEUM FUEL OIL COMPOSITION OF IMPROVED STABILITY HAVING A BOILING POINT RANGE BETWEEN 300 AND 700* F. AND CONTAINING AT LEAST 10 VOLUME PERCENT OF PETROLEUM HYDROCARBONS DERIVED FROM CRACKING OPERATIONS AND TO WHICH HAS BEEN ADDED FROM 0.001 TO 1.0 WEIGHT PERCENT OF A TERTIARY ALKYL PRIMARY AMINE HAVING 8 TO 30 CARBON ATOMS WITH A TERTIARY CARBON ATOM ATTACHED DIRECTLY TO THE AMINE GROUP AND FROM 0.001 TO 0.5 WEIGHT PERCENT OF AN OIL SOLUBLE ADDITIVE COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (A) A PHOSPHOSULFURIZED HYDROCARBON OBTAINED BY TREATING SUBSTANTIALLY OLEFIN FREE LUBRICATING OIL BRIGHT STOCK HAVING A VISCOSITY OF BETWEEN 150 AND 250 SSU AT 210*F. WITH FROM 5 TO 25 WEIGHT PERCENT OF A PHOSPHORUS CONTENT OF FROM FROM 375 TO 475*F. TO YIELD A PHOSPHOSULFURIZED HYDROCARBON HAVING A PHOOSPHORUS CONTENT OF FROM 2 TO 6 WEIGHT PERCENT, AND (B) LECITHIN, SAID FUEL OIL COMPOSITION HAVING IMPROVED STORAGE STABILITY CHARACTERISTICS WHEN IN CONTACT WITH DELETERIOUS METALS THAT INDUCE INSTABILITY BY THE FORMATION OF SEDIMENT. 